Oliver Braun - Multibody Simulation using sympy, scipy and vpython
[20 July 2015]
[Bilbao, Euskadi, Spain]
The talk is about the implementation of multibody simulation in the
scientific python world on the way to a stage usefull for engineering
and educational purposes.
Multibody simulation (MBS) requires two major steps: first the
formulation of the specific mechanical problem. Second step is the
integration of the resulting equations.
For the first step we use the package sympy which is on a very
advanced level to perform symbolic calculation and which supports
already Lagrange's and Kane's formalism. The extensions we made are
such that a complex mechanical setup can be formulated easily with
several lines of python code. The functionality is analogous to well
known MBS-tools, with that you can assemble bodies, joints, forces and
constraints. Also external forces even in a cosimulation model can be
added on top. The second step, the integration is done via ode-
integrators implemented in scipy.
Finally for visual validation the results are visualized with the
vpython package and for further analytics with matplotlib.
Conclusion: not only highly constrained pendulums with many rods and
springs but also driving simulation of passenger cars an be performed
with our new extension using python packages off the shelf.